Localization and symbiotic status of probiotics in the coral holobiont

Corals establish symbiotic relationships with microorganisms, especially endosymbiotic photosynthetic algae. Although other microbes have been commonly detected in coral tissues, their identity and beneficial functions for their host are unclear. Here, we confirm the beneficial outcomes of the inoculation of bacteria selected as probiotics and use fluorescence in situ hybridization (FISH) to define their localization in the coral Pocillopora damicornis. Our results show the first evidence of the inherent presence of Halomonas sp. and Cobetia sp. in native coral tissues, even before their inoculation. Furthermore, the relative enrichment of these coral tissue-associated bacteria through their inoculation in corals correlates with health improvements, such as increases in photosynthetic potential, and productivity. Our study suggests the symbiotic status of Halomonas sp. and Cobetia sp. in corals by indicating their localization within coral gastrodermis and epidermis and correlating their increased relative abundance through active inoculation with beneficial outcomes for the holobiont. This knowledge is crucial to facilitate the screening and application of probiotics that may not be transient members of the coral microbiome.

IMPORTANCE

Despite the promising results indicating the beneficial outcomes associated with the application of probiotics in corals and some scarce knowledge regarding the identity of bacterial cells found within the coral tissue, the correlation between these two aspects is still missing. This gap limits our understanding of the actual diversity of coral-associated bacteria and whether these symbionts are beneficial. Some researchers, for example, have been suggesting that probiotic screening should only focus on the very few known tissue-associated bacteria, such as Endozoicomonas sp., assuming that the currently tested probiotics are not tissue-associated. Here, we provide specific FISH probes for Halomonas sp. and Cobetia sp., expand our knowledge of the identity of coral-associated bacteria and confirm the probiotic status of the tested probiotics. The presence of these beneficial microorganisms for corals (BMCs) inside host tissues and gastric cavities also supports the notion that direct interactions with the host may underpin their probiotic role. This is a new breakthrough; these results argue against the possibility that the positive effects of BMCs are due to factors that are not related to a direct symbiotic interaction, for example, that the host simply feeds on inoculated bacteria or that the bacteria change the water quality.

Amperozide, a 5-HT2 antagonist, attenuates craving for cocaine by rats

Amperozide, a novel 5-HT2 receptor antagonist with little affinity for the dopamine receptor, suppresses the intake of alcohol in rats without affecting food intake or inducing other side effects. Because of these actions, amperozide was examined for its efficacy on the oral preference by the rat for a solution of cocaine. In this study, rats were selected for their voluntary consumption of at least 10 mg/kg of cocaine per day in a two-choice paradigm. A solution of 0.02% to 0.06% cocaine plus 0.03% saccharin in water was offered to each animal simultaneously with a solution of only 0.03% saccharin in water. The consumption of food and both fluids, as well as body weight, was recorded daily for three successive periods: 4 days of pretreatment baseline; 3 days during injections of either amperozide or the saline vehicle solution; and 4 days postinjections. Amperozide was administered SC twice daily in a dose of 0.5, 1.0, or 2.5 mg/kg. The volitional intake of cocaine was significantly reduced not only during the 3-day period of injections of amperozide but also during the 4-day posttreatment period. Amperozide exerted little or no effect on the intake of food or on body weight. Radioligand binding experiments confirmed that amperozide has at least a twentyfold greater affinity for 5-HT2 receptors in the frontal cortex of the rat, as compared to striatal DA1 and DA2 receptors, with the proportion value similar to that of the 5-HT2 receptor antagonist, ritanserin.(ABSTRACT TRUNCATED AT 250 WORDS)

Parental psychopathology and children's adjustment to leukemia

OBJECTIVE

The primary purpose of this study was to examine the relationship between parental psychopathology and psychosocial functioning of children in whom acute lymphocytic leukemia (ALL) has been diagnosed.

METHOD

The sample consisted of 61 mother-child dyads. Twenty-one (34%) mothers met DSM-III-R criteria for at least one psychiatric disorder based on a Structured Clinical Interview for Diagnosis (SCID).

RESULTS

Findings revealed that compared with children whose mothers did not meet DSM-III-R criteria for a psychiatric disorder, children with mothers who evidenced a psychiatric disorder self-reported more anxiety and a maladaptive attributional style and were reported by their mothers as evidencing more depression and a range of internalizing behavioral symptoms.

CONCLUSIONS

Although our earlier research suggested that ALL children show relatively few symptoms of psychopathology, the present report reveals high rates of psychiatric difficulties in the mothers of ALL youth. These findings and their implications are discussed within a model that incorporates behavioral pediatrics and developmental psychopathology.

Geographic classification of dengue-2 virus strains by antigen signature analysis

Dengue-2 virus strains from different locations were compared by T1-RNAse-resistant oligonucleotide fingerprinting and antigen signature analysis. The latter technique involved construction of radioimmunoassays using monoclonal antibodies that recognize nine distinct dengue-2 type-specific and flavivirus cross-reactive epitopes over a range of antigen concentrations. A statistical method was used to align unknown dengue antigen concentrations in different strain preparations, allowing comparison of binding profiles. Twenty-six dengue-2 virus strains were separated into five distinct groups (topotypes) on the basis of unique RNA fingerprints. Two of these were represented by New Guinea C, the prototype virus isolated in 1944, and a Philippine strain; others were segregated on the basis of greater than or equal to 80% shared oligonucleotides into similarity groups representing Burma/Thailand (8 strains), Puerto Rico (12 strains), and Jamaica (4 strains). Signature analysis of the prototype and four geographic topotype strains revealed striking antigenic differences. In contrast, a high degree of antigenic similarity was found among strains from the same geographic region. Variation between antigenically distinct strains occurred at both type-specific and group-reactive epitopes, but the widest differences appeared at group-reactive determinants. Signature analysis provides a more rapid and simpler means than RNA fingerprinting of monitoring changes or new introductions of dengue virus populations in a geographic region.

Multisite monoclonal immunoassay for dengue viruses: detection of viraemic human sera and interference by heterologous antibody

A monoclonal radioimmunoassay (RIA) was developed for detection of dengue virus in infected cell culture fluids and blood samples from dengue patients. Antibodies used to construct the RIA were selected on the basis of high binding avidity, the demonstration of synergism in competitive binding assays and empirical trials with different antibody combinations. Optimal binding of all four dengue virus serotypes was achieved by use of a flavivirus group-reactive and a dengue virus complex-reactive antibody as radiolabelled probe. A 'simultaneous sandwich' format and prolonged (18 h) incubation at 37 degrees C yielded optimal results. The limit of sensitivity of the RIA for detection of dengue type 2 virus was 2.7 log10 mosquito 50% infectious doses (MID50). The assay was tenfold more sensitive for dengue type 2 than for dengue types 1 and 3 viruses and 100-fold more sensitive than for dengue type 4 virus. Specificity, assessed using over 500 disease control human sera, was increased by addition of monoclonal anti-tetanus blocking antibodies, resulting in a false positive rate of only 0.2%. Heterologous dengue virus antibodies were shown to inhibit the RIA in assays performed with artificial immune complexes. Acute phase human sera containing 10(4.2) to 10(7.6) MID50 but no detectable antigen by RIA, were also shown to inhibit binding of the homologous dengue virus serotype; this effect was attributed to heterologous antibody from a prior infection. Among 116 viraemic sera from dengue patients, the RIA was positive in 43 to 47% of patients with dengue type 1, 2 or 3 infections but in only 10% of the dengue type 4 cases. Virus was more frequently detected in cases of primary infection (54%) than in cases of superinfection (16%). Despite the limitations imposed by immunological interference, the antigen capture RIA appears useful as a rapid diagnostic technique for dengue surveillance.

Sensitive and specific monoclonal immunoassay for detecting yellow fever virus in laboratory and clinical specimens

A solid-phase radioimmunoassay (RIA) was developed for the detection of yellow fever (YF) virus in infected cell culture supernatant fluid and clinical samples. The test employed a flavivirus group-reactive monoclonal antibody attached to a polystyrene bead support and a radiolabeled type-specific antibody probe in a simultaneous sandwich RIA format. Optimal assay conditions specified a 16-h incubation at high temperature (45 degrees C). Monoclonal antibody to tetanus toxoid was added to the radiolabeled probe to inhibit nonspecific binding. The sensitivity of the assay for cell culture-propagated virus was 2.0 log10 50% mosquito infectious doses per 100 microliters or 100 pg of gradient-purified virion protein per 100 microliters. Specificity, assessed with human sera from 512 patients with liver diseases other than YF, including acute viral hepatitis, showed a false-positive rate of 0.0 to 0.6%. Sera from experimentally infected rhesus macaques containing greater than 3.0 log10 units/100 microliter of YF virus were positive by RIA. Sera and liver tissue from human patients were found to be positive.